Phonographic apparatus



Oct. 17, 1939. E. c. GUEDON PHONOGBAPHIC APPARATUS Filed April 30, 1958 lmaentor Emile C. Guedon dnorneg Patented Oct. 17, 1939 "UNITE-D- sr r ruonoemmc Arr-m'ms Emile G.'Guedon, Audubon, N. 1., assignor to Radio. Corporation of Delaware Application April 30,

. 4 Claims.

turing tolerances, nor is it expedient,generally, I

to observe the care taken in the manufacture of more expensive apparatus. As a result, it is frequently found to be the case that the mountings heretofore provided for pickup arms have been such as to give rise to rattling of the parts with accompanying obnoxious disturbances in the reproduced sound. g The primary object of my present invention is to provide an inexpensive pickup arm mounting which will be free from the foregoing difliculties. More particularly, it is an object of my present invention to provide an improved pickup arm mounting which is free from rattles and which has a low resonance frequency. Another object of my present invention is t provide an improved pickup arm mounting as aforesaid which will automatically take care of production variations and which will provide adequate bearing structure for the pickup arm.

Still another object of my present invention is to provide an improved pickup arm mounting as aboveset forth which is inexpensive of manufacture, which readily lends itself to rapid, economical quantity manufacture and on which the pickup arm can be mounted easily and quickly.

In accordance with my present invention, I provide a vertically extending bushing in which a pin or the like is mounted for rotation, the pin carrying a substantially U-shaped member which extends upwardly toward the pickup arm. This member has fixed thereto a U-shaped spring which carries, adjacent the free ends of the arms of the U, a pair of oppositely extending, aligned,

conical bearing members which are fitted into aligned openings in the pickup arm, the resilience of the spring alone serving to retain the conical bearings in the aforesaid openings. The arms of the substantially U-shaped mounting member may serve as stop means for limiting the pivotal movement of the pickup arm'on the conical bearing members. The spring member is preferably of such flexibilitythat the resonance frequency of the pickup arm is lowered, while the resilience of the spring is suflicient to automatically take care of production variations and to insure a bearing without play, and therefore one which is free of rattles.

The novel features that} considercharacteristic of my inventionare set forth with particu- America, a corporation of 1938,8er1al myzoazsr larityin the appended claims. The invention itself, however, both as to its organization and method of operation, together with additional objects and advantages thereof, will best be understood from the following description of several embodiments thereof, when read in connection with the accompanying drawing, in which Figure l is a top plan view of a pickup arm and mounting therefor constructed according to my present invention,- l Figure 2 is a side elevation thereof, and Figure 3 is a similar view of a slightly modified form of my invention.

Referring more particularly to the drawing, wherein similar reference characters designate corresponding parts throughout, I have shown, in Figure 2, a motorboard I in which is set a bushing 3 which receives a shaft or pin 5 for rotation therein. Fixed to the upper end of pin 5 is a substantially U-shaped supporting member. 'I' having a pair of upwardly extending arms Ia and lb. To the arm lb is fixed a U-shaped spring 9 which lies in a plane angularly related to the plane of the U-shaped member I and which car-,- ries, adjacent the free ends of its parallel arms, a pair of outwardly directed conical bearing elements H, the bearing elements H being axially aligned with each other on an axis normal to the axis of rotation of the pin 5 and being received within a pair of aligned openings I3 provided adjacent one end of a pickup arm I 5 which, in transverse cross section, has the shape substantially of an inverted U, thereby being hollow. As clearly shown in Fig. 2, the spring 9 is concealed within the pickup arm l9 when the latter is mounted thereon in reproducing position. The larger bases of the bearing elements II are of considerably greater diameter than thediameter of'the openings 03, and the elements II are retained in the openings i3 solely by the resilience of the spring member 9. It will be apparent, therefore, that very strict tolerances need not be observed in the manufacture of the parts, and that the parts may be easily and quickly assem bled merely by pressing the parallel arms of the spring member 9 together, and permitting the bearing members Ii to snap into the openings E3. The arms la and lb of the rotatable member l eflectively serve as stop members to limit pivotal movementof the arm IE on the aligned bearing-members II relative to a record R.

In Figure 3, I have shown a slightly modified form of the invention to adapt it for use in phonographs of the automatic type wherein records are changed automatically. In this case, the spring 9 is mounted on the-shorter arm la of the member 1, and the pickup arm I5 may be automatically raised from the record R at the completion of playing thereof by means of a suitable cable I"! and associated mechanism of the type disclosed, for example, in U. S. Patent No. 2,094,255. If desired, the arm 1b may be made of resilient material and of a length sufficient to engage the pickup arm [5, so as to relieve the weight thereof upon the record and thus control the needle pressure on the record.-

Although I have show and described but two embodiments of my invention, I am fully aware that many modifications thereof are possible and I therefore desire that my invention shall not be limited except insofar as is made necessary by the prior art and by the spirit of the appended claims.

I claim as my invention:

1. In phonographic apparatus, a hollow pickup arm, and a mounting therefor, said mounting comprising a rotatable member constituted in part by a U -shaped member, a U-shaped spring carried by said rotatable member, said spring lying in a plane angularly related to that of said U-shaped member, and a pair of aligned, oppositely disposed bearing elements on the free ends of the arms of said spring, said arm being mounted on said bearing elements for pivotal movement thereon, said spring being concealed within said pick-up arm, and the arms of said U-shaped member extending toward said arm 3. In a phonograph, a pick-up arm, and a mounting therefor, said mounting comprising a rotatable member having an upwardly extending portion, a u shape'd spring carried by said rotatable member, said spring lying in a plane angularly related to that of said portion, and a pair of aligned, oppositely disposed bearing elements on the free ends of said spring, said arm being mounted-on said bearing elements for pivotal' movement thereon, and said portion extending toward said arm and constituting a stop member for limiting pivotal movement of said arm on said bearing elements.

4. The invention set forth in claim 3 characterized in that said pick-up arm is hollow, and characterized further in that said spring and at least a part of said upwardly extending portion are concealed within said arm.

EMILE 'c. GUEDON. 

